What's new in Android 4.4

• Android 4.4 is designed to run fast, smooth, and responsively on a much broader range of devices than ever before.
• Android 4.4 targets to run efficiently, even on low-memory devices. Core system processes are trimmed to use less heap, and they now more aggressively protect system memory from apps consuming large amounts of RAM.
• When multiple services start at once — such as when network connectivity changes — Android now launches the services serially, in small groups, to avoid peak memory demands. 
• New NFC capabilities through Host Card Emulation.
• Printing framework 
• Storage access framework
• Low-power sensors
• Step Detector and Step Counter Read more about it here.

Must Read : Updates about new APIs...

See the Changes from API 18 - API 19


Below are links for downloading the developer tools API level 19, offline, alternatively you can download from your SDK Manager.

Download Developer Tools, API - 19

SDK Platform API - 19 (Android SDK Platform 4.4)

  ~\..\android-sdk-windows\platforms\android-19\ (Unzip files)
      Android-19_r04.zip 

     Android-19_r03.zip  
      Android-19_r02.zip  
     Android-19_r01.zip  


Google API for Maps, usb accessory, media effects. API - 19

  ~\..\android-sdk-windows\add-ons\ (Unzip files)

      Google_apis-19_r03.zip  

      Google_apis-19_r02.zip
     Google_apis-19_r01.zip   

Samples for SDK - 19
 
 ~\..\android-sdk-windows\samples\android-19\ (Unzip files)  
      Samples-19_r06.zip  

      Samples-19_r05.zip   

      Samples-19_r04.zip  

      Samples-19_r03.zip  
      Samples-19_r02.zip  
      Samples-19_r01.zip   


ARM EABI v7a System Image, API - 19

  ~\..\android-sdk-windows\system-images\android-19\( Unzip files)
      Armv7a-19_r02.zip  

      Armv7a-19_r01.zip  


Intel x86 Atom System Image, API - 19

  ~\..\android-sdk-windows\system-images\android-19\( Unzip files)
      Intel_x86_atom_r02.zip  
     
       Intel_x86_atom.zip 

Intel x86 Atom Google API(for Maps), API - 19

  ~\..\android-sdk-windows\add-ons\( Unzip files)
     Intel_Google_APIs_x86_atom_r08.zip  

      Intel_Google_APIs_x86_atom_r07.zip 

      Intel_Google_APIs_x86_atom_r06.zip 

      Intel_Google_APIs_x86_atom_r05.zip 

      Intel_Google_APIs_x86_atom_r04.zip 

      Intel_Google_APIs_x86_atom_r03.zip
      Intel_Google_APIs_x86_atom_r02.zip 
      Intel_Google_APIs_x86_atom_r01.zip



Sources for Android SDK, API - 19

  ~\..\android-sdk-windows\sources\android-19\ (Unzip files)
      Sources-19_r02.zip 

     Sources-19_r01.zip 
   


Docs for Android SDK API - 19
 (replace the docs folder, but, this will be of no use, please refer online)



 ~\..\android-sdk-windows\docs\ (Unzip files)
      docs-19_r02.zip 

      docs-19_r01.zip